Saturday 17 August 2013

Ballonts in Gas Giants ('Ballonts V')

More ballonts? Well, yes: I had previously explored whether it is possible to produce a fairly small life form floating around using the lighter-than-air mechanism, but there were some loose ends left. As the last one was posted in 2011, it may be wise to recapitulate a bit (or work your way up from here, through here, to this one).

Click to enlarge; copyright Gert van Dijk
The image above show a scene on Earth on sea level at about 20 degrees Centigrade. A default local sophont (let's call him 'Julius') holds a stick indicating two meters. There is also a balloon with a radius of 62.03 cm. Why 62 cm? Because that yields a sphere with a volume of exactly one cubic meter (m^3). The skin is made of a 0.1 mm thick mylar-like material with a mass of 0.5802 kg. The balloon is filled with the lightest possible gas, hydrogen. Hydrogen has a density of about 0.0899 kg/m^3 at 20 degrees, while the air has a density of 1.2019 kg/m^3. So, the 1 m^3 balloon has 0.0899 kg of hydrogen in it, while the corresponding volume of air has a mass of 1.2019 kg. The balloon can therefore lift 1.2019-0.0899 = 1.1120 kg (that is the part needed to understand how balloons work). As the skin masses 0.5802 kg, that leaves 1.1120-0.5802 = 0.5318 kg to build a nice body out of. That is not a nice big body at all; given a body density of 1.1 kg/m^3, which is like our bodies a bit heavier than water, we can hang a spherical body with a radius of just 4.9 cm under our balloon, and the ensemble will then just float. Of course, a real animal would have tentacles and limbs and mouthpieces etc.

As said, I wanted ballonts with a body mass of, say, 10 kg but with only a moderately sized sac. As the example above shows that does not work on Earth. The hydrogen inside the balloon cannot be made lighter, but we can alter the atmosphere outside it; this is speculative biology after all. There are two ways of doing so: the first is to stuff the atmosphere with very heavy gases such as argon, but such elements are quite rare in the universe. The other is to add mass by increasing pressure, as that will squeeze more mass in the same volume. So, let's explore gas giants, where high pressures are easily found.


Click to enlarge; Source: Brian Vanderwende University Colorado
The pictures above show information about 'our' gas giants: the composition of the atmosphere, the temperature and the pressure. Not surprisingly, atmospheric pressure increases the deeper you descend into the atmosphere. For our first try, we should perhaps be a bit conservative and stay with biology in fluid water. A temperature of 20 degree centigrade should not upset Julius; it is the same as 293 degrees Kelvin. For Jupiter, the 293 Kelvin zone results in an atmospheric pressure of some 9-10 times that of Earth, which sounds like a decent start. Instead of jumping in directly, it may be easier to take it in stages, building on the Earth model shown above.

Click to enlarge; copyright Gert van Dijk
The image above shows the first step: Earth's atmosphere is changed to a Jovian one at one atmosphere and 20 degrees centigrade. Internet sources show that the Jovian atmosphere consists of about 86% hydrogen, 14% helium and a smattering of other compounds. Based on the densities of hydrogen (0.0899 kg/m^3) and helium (0.1664 kg/m^3) the density of a 86:14 hydrogen/helium mixture should be 0.1006 kg/m^3. Oops! That is only very slightly denser than pure hydrogen, which we need to fill the ballont with! If you thought Earth air was a bad medium for ballonts, think again. So what are the effects? Well, the liftable mass is 0.1006-0.0899= 0.0107 kg. Remember that the skin had a mass of 0.5802 kg? There's nothing left for a body, so this balloon is not getting off the ground at all.

Click to enlarge; copyright Gert van Dijk
We were aiming for high pressures, so let's increase the pressure to 10 atmospheres. The mass in the balloon will be 10 times higher, and so will the mass of the equivalent volume of air. So the liftable mass also becomes 10 times larger: 10 x 0.0107= 0.107 g. That's still nowhere near the mass of the skin, so this balloon isn't going up either.

Click to enlarge; copyright Gert van Dijk
Let's leave Jupiter and find a ballont-friendlier place. Uranus and Neptune have atmospheric pressures about 50 times Earth's at the 293 Kelvin range. That's better, and apparently the Uranian atmosphere is heavier, with 2.3% methane thrown in. I make the density of its mixture to be 0.1148 kg/m^3 at 1 atmosphere and at 20 degrees C. So, the 1 m^3 balloon can lift 0.1148-0.0899 =0.0249 kg. That is not good enough, but at 50 atmospheres the liftable mass is 50 times that, or 1.2450 kg. Subtracting the skin leaves 0.6648 kg. Finally, a floating balloon! Hurrah!

Or perhaps not 'hurrah', as that is only a tiny bit more than what we had on Earth to start with... Let's go up to 200 atmospheres in Uranus: the liftable mass, skin already subtracted, would be 4.4 kg, and at 500 atmospheres it would be 11.9 kg. Finally we have what we wanted!

Well, not really; these values are not yet adapted for the lower temperature. Julius is left behind, as we need a wholly new biochemistry. The atmosphere is now also so soupy that you would not want to think about the wind or moving in it. Adding even more problems, there is another potential disaster lurking in these gas giants: gravity. The gravity constant for Uranus is nice at 8.85 m.s^-2, a bit less than Earth's at 9.8 m.s^-2. But Jupiter has a value of over 25, so if you thought you could get away with a nice fragile ballont there, waving its slight tendrils through the air and looping in prey with slender tentacles, think again: the animal would need the sturdy limbs befitting a 2.5G environment.

It really does seem as if the universe is trying to sabotage ballonts, doesn't it? Gas giants do have high atmospheric pressures, but their beneficial effects are counteracted by the fact that the atmospheres consist of very light elements. It seems that the only way to get a viable (pun intended) ballont on a Jovian planet is to make the ballont extremely large. But that is where we started... I am beginning to think that there may not be any appreciable advantage in locating ballonts in gas giants, even though science fiction is full of them. They do about as poorly there as they do on terrestrial planets, meaning they can in fact work, but they have to be big, very big. Perhaps gas giants have other advantages for ballonts: there's certainly a lot of atmosphere to play with in them.

Ca I still claim that ballonts are so common in gas giants that they are boring? Yes, but they will be big, as usual; perhaps that's what makes them boring. The best way out for small ballonts seems to be offered by terrrestrial planets with heavy gases and high pressures: Venusian analogues? Perhaps there will be a 'Ballonts VI', one day.   

23 comments:

contemplatecast said...

Have you considered making ballonts plants rather than animals.

Sigmund Nastrazzurro said...

Contemplatecast: I had indeed toyed with the idea of having plant as well as animal ballonts. Plants might derive a benefit in that the large sac area could be used as a site for photosynthesis, and the body mass might be kept low. The main reasons to prefer animals are that landing to take in water and nutrients seems more feasible for an animal than a plant, and, well, animals provided more drama...

Zerraspace said...

Strangely, when last we members of the Speculative Evolution forum explored the possibility of life developing on gas giants, we never did get to trying out ballonts: the organisms we thought of were sheet-like, using enormous surface area to catch the lighter wind and making use of high pressure high speed currents to keep them aloft. It seems just as well that we didn't think of these.

I decided to comment here because such a "Ballonts VI" entry, relying on Venusian analogues, seems particularly relevant to my current speculative evolution project, the Super-Earth Meios (some art of which I've already shown you on Deviant Art), so I've already explored many of these issues. Furthermore, this world allowed me to explore the issue of heavy gravity, but in this case the ballonts make due with apparently flimsy appendages: this is because they deal mainly with other ballonts, so weight is not an issue.

I can confirm that such environments will allow lighter-than-air flight, at least from a purely physical aspect (if you're willing to bear with high pressures). Meios has an 80% CO2 atmosphere with pressure of 340 bars on the surface (this high pressure is due mostly to gravity - at Earthly gravity, it would be 95 bars, much like Venus): by your calculations, a quarter-meter radius balloon filled with hydrogen with a one millimeter thick Mylar-like membrane would be able to lift roughly 6.02 kilos (after deducting the weight of the hydrogen and membrane; the membrane masses only 0.94 kg, its hydrogen pressurized to match the surroundings only 0.55 kg): this seems more than enough to be practical, and even allows ballonts that are not completely dominated by their balloons. It definitely helps that CO2 is significantly denser than air, but practically this would have other effects on the ecosphere: CO2 becomes an acid in water and as a result, Meios' oceans have a pH of 3 (that's not far from stomach acid)...

Of course, flying in this atmosphere is more like swimming: 340 bars is equivalent to the pressure some 3 kilometers underwater. We have organisms living deeper on Earth, so it can be done. However, there are further problems when gravity is considered: higher gravity allows for higher pressures, but also reduces scale height, which is to say that pressure lowers off dramatically as you go higher. Only 12 km off Meios' surface, the pressure is only 1 bar, and by 15 km, it's less than what you would find on Earth.

Christmas Snow said...

Since your latest posts about ballonts, I had some time to think about the biomechanics and I have found some interesting aspects:

Dense earth-like atmosphere: Something like Venus or an oxygen-rich version of it may be common in the universe. I assume that strong winds caused by the dense atmosphere will force many creatures to become lighter-than-air ballonts. The densest thing we have on Earth is water, where body tissues are hardly denser than water. This allowed static lift using a float-bladder in fish.

Dense Jovian atmospheres: Nothing is lighter than hydrogen than hot hydrogen itself. The idea of using body heat to maintain a hot air balloon seems wasteful and unlikely in a Jovian atmosphere. The same energy can be channeled to flight capabilities instead, making ballonts too slow for predators, vulnerable and inefficient.

Balloon volume and load bearing: Lifting force proportional to the cube of the balloon’s radius, yet surface area of connective tissue (connecting body to balloon) is proportional to the square of the radius, meaning the bigger the creature is, the more stress this connective tissue must endure to carry body weight. It is possible use tendons and to distribute tension along balloon’s surface, but this requires a thicker membrane, hence heavier envelope! Here is an example of tendons (Load curtains) in a non-rigid airship:
http://www.airship-association.org/cms/files/web/Skyship/structure.gif

Shape: Streamlining requires an elongated cigar-shaped or squid-shaped body plan.

Tissue maintenance: The large ballonts will have a serious problem: Balloon membrane needs gas exchange (respiration) and nourishment. How blood circulation is maintained in a thin membrane that spreads over a few square meters if not more? Does the membrane have many small hearts, or does it feed from the main heart? Can this ballont also breathe through its skin? If skin is damaged and lifting gas leaks, how can the ballont heal itself and return to the air?

Ronan said...

I wonder if there's any way one could get away with jettisoning the main source of extra mass for a ballont, and create a waterless organism? I'm imagining something very like a gigantic cell, using gas rather than liquid as its internal fluid. Problems arise, of course; membranes will have to be based on something other than molecular polarity, and dissolving complex organic compounds in the fluid is right out. One could sidle around both problems by putting this putative creature in a "sea" of supercritical fluid capable of dissolving different compounds (So, basically Venus' surface), but then it becomes more an extremely exotic fish than a true flying animal (or xerobacterium, at least). I'll have to think about this some more; natural selection is an immensely powerful and versatile tool, and there's got to be some way to evolve and maintain a gas-based organism.

Sigmund Nastrazzurro said...

Zerraspace: well, seeing you've done it already, I wonder whether a future post on Ballonts VI is still needed or useful. Before having done the math I would have guessed that the high pressures in gas giants would have outweighed the disadvantages of their light atmospheres, but not so. I guess the approach you have taken is the only one left, combining high pressures with dense atmospheres.
As you wrote, under such circumstances moving through 'air' must be a lot like swimming, and that led me to think that the most viable way to have ballonts is to use animal with a swim bladder submerged in water... but that feels like cheating.
Does the gas under these conditions change into a 'supercritical fluid'; that's something I meant to explore further, but perhaps you have already done so.

Christmas Snow: In an earlier post I explored whether heating hydrogen helps: a bit, but as hydrogen is so light, the gain is probably not worth the energy involved.
I agree that building a proper ballont would very probably not involve a single perfect sphere. I may have mentioned the reasoning previously, but I only used a sphere here as it results in the best volume to surface ratio: if a perfect sphere will not work as a balloon, other shapes certainly won't.
As for membrane maintenance: the easiset solution for that one might be to use a dead membrane! If an animal would use various sacs, sacs can be as light as possible. Of course, this means growing new ones, filling them, etc.

Sigmund Nastrazzurro said...

Ronan: this is funny: your comment came in while I was typing away at my answer, and I read it after posting mine. There you are, mentioning supercritical fluids and the 'fishiness' of ballonts under Venusian circumstances. Great minds etc., I suppose.
As for basing life on a gas rather than on a fluid, that is interesting. I haven't got an answer, and certainly will have to find out more about supercritical fluids first.

Spugpow said...

Perhaps a the ideal lifestyle for a ballont is actually grounded (or arborial). I could imagine a lighter than air organism "hanging" from the ground using tentacles the same way a sloth hangs from the trees, and gently swaying from tentacle-hold to tentacle-hold. Freed from supporting their own weight, these tensile organisms could be far more efficient than their conventional counterparts.

Ronan said...

For whatever it might be worth, based on its phase diagram, CO2 does exist as a supercritical fluid at Venus' surface, covering the lowlands of the planet with a...I don't know if we even have a word for it. An atmosea? Even more interesting, the phase diagram of CO2 is such that given the right pressures, one could easily get an atmosphere with surface conditions below the boiling point of water, but above the temperature and pressure at which CO2 goes supercritical. Given that supercritical CO2 is more than capable of dissolving a variety of different compounds, you'd end up with a bizarrely "salty" atmosphere--or rather, less salty and more messily organic, with lots of nonpolar compounds drifting through the "air."

Anonymous said...

a thought...
perhaps we can get around the size barrier by allowing that, even if ballonts can't *arise* in gas giants or other worlds...that they can evolve and thrive there, after other organisms (visiting from other worlds, or native there themselves) create and release the ballonts in the gas giants.

-rodlox.

Anonymous said...

>The idea of using body heat to maintain a hot air balloon seems wasteful and unlikely in a Jovian atmosphere

could the body hold and use the heat gathered from its enviroment? (a Jovian version of swimming in warm water/sunning on a riverbank)

-Rodlox.

Sigmund Nastrazzurro said...

Spugpow: a very interesting idea; when Furaha still had lost of ballonts, I envisaged them dropping down every now and then to take in water and food. What you describe means that they would spend more time on the ground than in the air. Why not indeed?

Ronan: I only had a minute or two to look up the combination 'Venus' and 'supercritical'. Aparently supercritical CO2 is used on Earth to dossolve many things, so it could certainly create a fascinating environment. Perhaps Zerraspace has already looked into this.
I have not yet seen anything about things such as the actual viscosity of this 'airy
fluid'.

Rodlox 1: True, but that requires a mechanism for ballonts to evolve elswhere too unless they are engineered. In gas giants they might first arise at depths of very high density and later colonise aereas of lesser pressure.

Rodlox 2: That might certainly work. Even my former Furahan ballonts were to have colour control in their skins, so they could warm up and cool down as required. But even so hot hydrogen offers only a slight improvement in liftable mass over cool hydrogen (I did the math in an earlier post)

Zerraspace said...

This message got so long the comment box refused to post it all together, so I have to post it in two pieces. Firstly, regarding ballonts and other atmospheres:

At Meiosian conditions (340 atm) the atmosphere is entirely superfluid: the critical point of oxygen is -118.6 C, 50.4 bar and that of nitrogen is -147 C, 34 bar, while that of CO2 is 31 C, 73.8 bar (I should note that its triple point, when liquid stage first appears, is -56.57 C, 5.19 bar). Essentially, so long as atmospheric pressure is below 34 bars and temperature is above freezing (effectively the boiling point for CO2 at this pressure), an atmosphere with the same constituents will be wholly gaseous and not superfluid.

Say at 30 bar with an atmosphere of similar composition to our own, a 10 cm radius ballont can carry 0.126 kilograms. By only 20 cm, it is carrying a full kilogram, and by 50 cm, it’s carrying 17 kilograms. A balloon one meter in radius can carry 139 kg, and even if you thicken the membrane to a full millimeter you can still hold 126 kilograms. In short, this is a world where man could fly with a balloon not much bigger than he is yet with no supercritical fluids involved (at this pressure, CO2 boils at -4.44 C, so outside the poles, it will be a gas rather than a liquid). If anything these figures suggest you could probably yield similar effects at a lower pressure. At merely 7 bars (about as high as you can get and still be breathable – albeit short term – for humans), a 10 cm radius balloon can still carry itself and an additional 18 grams (which is about the weight of the membrane and hydrogen combined). By 35 cm, it can carry just over a kilogram, by 50 cm, it is carrying 3.73 kg, and by a full meter, it is carrying 31 kg. Smaller ballonts will probably be limited in scope here (though I suspect 18 grams is just fine for a seed-like ballont), but there is good potential for mid-range ballonts. I should note that these both assume an essentially Earth-like atmospheric composition: a true Venusian analogue, higher in CO2, would allow heavier weights to be carried.

If you really wanted to push your luck, you could try a xenon-rich atmosphere, as Oceaniis did: this noble gas has a density of 5.894 g/L or 5.894 kg/m3, about 5 times that of air, and is nontoxic, though it is an anesthesiac (so I suggest you bring your own air tank visiting all the same). In an 80% xenon 20% oxygen atmosphere at 1 bar (density of about 5 kg/m3), the 10 cm ballont can lift itself and another 5 grams, by 40 cm it is carrying a full kilo, and by a full meter it is carrying 22 kg. Hence, we may have reasonably-sized ballonts at an Earth-like pressure, hurrah! (That being said I should note that it’s all but impossible that we’re ever going to find such an atmosphere: xenon is incredibly rare in the universe…)

Zerraspace said...

Secondly, regarding supercritical fluids and viscosity:


As of yet I have not found any mention of supercritical nitrogen or oxygen as solvents; only for supercritical CO2, and I will admit I did not look into its capabilities all too deeply, figuring that it would be a poor solvent compared to water, or at least poor enough to create distinct aerial and aquatic environments (besides the aspect that even as a supercritical fluid, liquid water would remain much denser than the atmosphere). This report (here http://www.epa.gov/ncer/science/tse/sos.pdf ) seems to confirm it, labeling it a “feeble solvent”, though I should note this is with regards to its industrial properties: to quote, it has “solvent power inferior to that of n-alkanes – very few polymers tested by Heller showed any significant solubility in carbon dioxide at moderate (<200 bar) pressures”. That being said N-vinyl formamide acts as an emulsifying agent, allowing such processes to occur more readily. The technical jargon is mostly beyond me, but important notes I could find are that supercritical CO2 cannot host strong bases as it will react with them, and the ability to react with amine groups limits the solubility of amino acids and enzymes (though in many cases it reacts reversibly). It is exceptionally good at dissolving silicones and fluorinated compounds, to the point that “effectively any catalyst could be rendered CO2-soluble if the fluorination of the ligands could be accomplished”. Inorganic compounds are mostly insoluble and noble metals dissolved in it act as catalyst for carbamate formation. If you can make any more sense out of it than I can, I would be most grateful, but I suspect we're going to need a chemist or chemical engineer...

Other information you might find interesting is that water solubility in supercritical CO2 is 2500 ppm (0.25%) for pressure below 100 bar, and viscosity of carbon dioxide at “liquid-like” densities is one tenth that of water. For air itself, viscosity seems largely linked with temperature, and to a lesser extent with pressure: this study here http://www.nist.gov/data/PDFfiles/jpcrd283.pdf gives exact figures on the 8th and 9th page over ranges of 85-2000 K and from 10 KPa to 100 MPa, but even this does not deviate by more than one order of magnitude. I doubt either figure would be of much impact for ballonts or potential fliers, as all but the smallest will have high Reynolds numbers, meaning that drag forces will always be dominant over viscous ones.

Sigmund Nastrazzurro said...

Zerraspace: impressive! I will try to make sense of the papers in the links you provided, but that will take time.
I must be missing something in your first post. You start with the Meiosian atmosphere at 340 atm., and later describe an atmosphere at '30 bar with an atmosphere of similar composition to our own'. Later you write that at 7 bar a balloon with a 1 meter radius can carry 31 kg. Is that still about Earth air and a hydrogen balloon at 7 times Earth atmosphere pressure (and 20 degrees centigrade)?

Zerraspace said...

Yes, that is exactly what I am referring to: for both 30 bar and 7 bar pressures, I assuming Earth-like air (78% nitrogen, 21% oxygen, 1% various) and a hydrogen balloon exposed to formerly mentioned pressures and at standard temperature. That being said, the atmosphere mentioned in the third paragraph is anything but Earthly: 1 atm of 80% xenon and 20% oxygen, breathable but likely to knock you out as soon as you inhale.

I merely gave the pressure of the Meiosian atmosphere – 340 bar – to accompany the critical points afterward, confirming that it is supercritical. Its relative composition is 81% CO2, 5% O2, 4% N2, 0.1% H2O vapor, with the remaining 9% is a mix of noble gasses and other oxides.

P.S. I've sent you an e-mail with further information relevant to the discussion.

Sigmund Nastrazzurro said...

If you read the last few posts, you might have received the impression that there was something wrong with the physics in the earlier series of posts on ballonts. I had a insightful discussion with Zerraspace regarding all this and this proved not to be the case, so ballonts stay where they are, on Furaha as well as on Meios (Zerraspaces's creation). As things stand now, terrestrial planets with high atmospheric pressures seem to be most amenable to ballonts.
As Charlie Brown would have said: 'sigh...'.

Anonymous said...

Glad to see a 'Ballonts V' and further discussion on the subject. Terrestrial planets with thick, possibly CO2-rich atmospheres are certainly the best way to go; a cursory look at the chemical components of a gas giant atmosphere demonstrates that they are unfortunately a poor environment.

I have often wondered whether CO2-rich planets somewhat similar to Venus, although cooler (of course) could be a common species of environment in the universe. These would certainly be very interesting environments for life; the most major problem with the idea, however, is that as Zerraspace mentioned, such worlds will have very acidic oceans due to dissolved CO2 and that this and similar phenomena within biology poses issues to life. There was a thread on the Speculative Evolution forums about the issue where the user Holbenilord pointed out several issues with survival in a CO2 rich atmosphere.

In recent times there have been many discoveries of super-Earth planets, occupying a mass range between that of Earth and our smallest gas giants. If these worlds have thick atmospheres, with large amounts of denser components such as N2 or CO2, they might be a suitable home for boringly abundant ballonts- though obviously if they are without a habitable surface, they will face the same problems in terms of abiogenesis and evolution of life as a gas giant.

In a CO2 rich atmosphere, nitrogen and oxygen are lifting gases, though obviously not as good as hydrogen. An interesting phenomenon on the colder gas giants is also that they're very good environments for hot-air balloons- if you can maintain something around room temperature within the lifting envelope on, say, Neptune, you'll have a lot of lifting power. That might be relevant for gas refinery platforms or even some sort of colonisation project, but life doesn't have the benefit of fusion power...

~
T.Neo

Sigmund Nastrazzurro said...

T.Neo. Thank you: I agree that the composition of gas giants' atmosphere conspires against them being a haven for ballonts; but past experience with 'balloon science' led me to do the calculations anyway rather than trust a quick look.
One of the things that taught me that lesson was an attempt to use a hot hydrogen balloon in air (see 'ballonts under pressure'): the problem with that is that hydrogen is so light that the mass you can spare by heating it does not amount to much. My hunch would be that hot hydrogen would also not have that much effect on a gas giant, but I haven't done the math on that one yet, and shouldn't trust hunches, not even my own...
I agree that terrestrial heavy planets seem to be the only haven for ballonts, and even there the biochemistry probably needs to differ enough from what we know to make ballonts floating in a human-friendly environment unlikely if not impossible.

Petr said...

Wow! I don't know which was more interesting - the post itself or the discussion in the comments.
I too have pondered the possibility of a gas-based life as opposed to a liquid-based life, but that was more of a mental exercise rather than a serious thing I'd argue for being actually possible.

That being said, I agree that venus-like planets could have interesting environments, and with acidic oceans, I'd imagine all marine lifeforms would be covered in a thick layer of mucus to protect themselves =)

One other type of planests that I think are interesting would be mars-like planets. cold deserts with thin air and strong radiation. Sounds hostile (but in comparison with acidic oceans, which is really the more hostile one?) but I think life on earth has proven that it finds a way against all odds.

One last thing. This is irrelevant to both, the discussion above and the post, but let me run with it.

What if mars was an earth-sized planet? it would be big enough to maintain a thick enough atmosphere, it would have plate tectonics, it would have water, but would it have dry desert-like continents like mars does, only with the oceans frozen over (presumably) or would it be a "snowball earth" (I know the term is used for a period in earth's history, but it fits anyway)
So what are your thoughts? What whould a big terrestrial planet look like when put in Mars' orbit?

Sigmund Nastrazzurro said...

Petr: If you go so far as to postulate life on a Venusian planet with an insanely high pressure and an acidic ocean, why not go all the way and let go of the demands of Earth's biochemistry? Personally I would need an enormous amount of 'handwavium' to come up with such a biochemistry (a subjects I do not know much about), but you could argue that the 'gaps' in the story might be less awkward than squeezing a biochemistry in an environment it might not be able to evolve in.

As for the 'Big Mars', again I am an amateur here. But, seeing how much circumstances on Venus and Earth differ through their different atmospheres, I wonder whether there is enough leeway there to give Mars a range of climates all the way from a frozen to a molten heel, with some pleasant stages in between.

Petr said...

On a different note, given we have a thick atmosphere made out of heavy gasses and a hydrogen-filled balloon, has anyone taken into consideration/made the calculation when taking into account how much hydrogen there would have to be in said balloon to counteract the outside pressure? surely on a planet with a thick dense atmosphere, the "normal" density hydrogen put in a balloon would implode like a submarine that descended too deep into the sea.

What I mean is, the actual weight of hydrogen that would have to be put in a balloon in a soapy atmosphere in order for it to not implode under the pressure would be greater than people put into consideration/calculation and the lifting ability of said balloon would be lower. I don't think the balloon is supposed to have a solid shell, but rather a flexible membrane tightenned by the inside pressure, and therefore my worries that the hydrogen would have to be pressured in the balloon to counteract the outside pressure of the atmosphere and therefore having a larger mass of hydrogen in the same space. if it had a shell, having vaccuum inside could potentially be even better than hydrogen, but I doubt that the shell could remain thin enough to allow for a buoyant organism and still not crack under the outside pressure. :)

Sorry for the ramble, this may be one of the least coherent comments I have made, and I apologize in advance.

Anonymous said...

Psst.. Hey. Check these out, might be a good lead for your reasearch.. Just thought i should tell someone there might be more to the story of earth's evolution than we currently know.

The possibilities could be as vast as some of the bio-luminescent creatures of the deep sea that light up when threatened. Much like the ones in this video (https://www.youtube.com/watch?v=XD7thJVRKmQ) only in LEO and the very upper atmosphere, as it would be safe to say that the very first life on this planet could have been formed IN our fledgeling atmosphere due to lightning and simple amino acids. Although this theory is not entirely plausible in the ocean (primordial soup theory) as to Stanley Miller and Harold Urey experiments concluded in 1953, but the original theory can be adapted to our new knowledge of our atmosphere and the vase exotic diversity of evolutionarily advanced bacterium that have been newly discovered to exist in our atmosphere. Why couldn't there be new pylums or possibly a new kingdom yet undiscovered on our planet do to our inability explore? We went to the deep sea and found a whole new frontier of biological discoveries that we never knew existed. Much like the American naturalist Louis F. de Pourtales and Scottish naturalist Charles Wyville Thomson who disproved Edward Forbes' theory of a lifeless (azoic) zone below 300 fathoms (1,800 feet, 548 meters) in 1867-1868. The “lifeless zone” in our atmosphere could be as horribly incorrect as it was for our oceans in the 1800's. Below are some interesting articles and videos that I belive to be leads to misidenifications of what most people are simple unaware, which the last video maybe an unfortunate occurance of such when the species is inderested or otherwise threatened like the deep sea creatures mentioned earlier.

https://en.wikipedia.org/wiki/Crawfordsville_monster (much like a whale going to the crushing depths of the ocean floor to die.. sad.)

http://www.livescience.com/18242-mysterious-blue-balls-fall-sky-england.html (possible eggs denote a life cycle)

https://www.youtube.com/watch?v=6frCAQ5OFxo (stated previously)

With warm wishes for your consideration,
-A Wandering Observer